Power switching module for battery module assembly

ABSTRACT

Disclosed herein is a power switching module for a battery module assembly constructed in a structure in which a plurality of rectangular battery modules, each having a plurality of battery cells or unit modules connected in series to each other, are stacked in the width direction (the longitudinal direction) and the height direction (the transverse direction) by at least twos such that the rectangular battery modules generally constitute a hexahedral structure (hexahedral stack), outer edges of the hexahedral stack are fixed by a frame member, and input and output terminals of the rectangular battery modules are oriented such that the input and output terminals of the rectangular battery modules are directed toward one surface (a) of the hexahedral stack, wherein the power switching module comprises an insulative substrate mounted to the surface (a) of the hexahedral stack in a coupling fashion, elements mounted on the insulative substrate for controlling voltage and current during the charge and discharge of the rectangular battery modules, and connection members mounted on the insulative substrate for interconnecting the control elements.

FIELD OF THE INVENTION

The present invention relates to a power switching module for batterymodule assemblies, and, more particularly, to a power switching modulefor a battery module assembly constructed in a structure in which aplurality of rectangular battery modules, each having a plurality ofbattery cells or unit modules connected in series to each other, arestacked in the width direction (the longitudinal direction) and theheight direction (the transverse direction) by at least twos such thatthe rectangular battery modules generally constitute a hexahedralstructure (hexahedral stack), outer edges of the hexahedral stack arefixed by a frame member, and input and output terminals of therectangular battery modules are oriented such that the input and outputterminals of the rectangular battery modules are directed toward onesurface (a) of the hexahedral stack, wherein the power switching modulecomprises an insulative substrate mounted to the surface (a) of thehexahedral stack in a coupling fashion, elements mounted on theinsulative substrate for controlling voltage and current during thecharge and discharge of the rectangular battery modules, and connectionmembers mounted on the insulative substrate for interconnecting thecontrol elements.

BACKGROUND OF THE INVENTION

Recently, a secondary battery, which can be charged and discharged, hasbeen widely used as an energy source for wireless mobile devices. Also,the secondary battery has attracted considerable attention as a powersource for electric vehicles (EV) and hybrid electric vehicles (HEV),which have been developed to solve problems, such as air pollution,caused by existing gasoline and diesel vehicles using fossil fuel.

Small-sized mobile devices use one or several battery cells for eachdevice. On the other hand, middle- or large-sized devices, such asvehicles, use a middle- or large-sized battery module having a pluralityof battery cells electrically connected with each other because highoutput and large capacity are necessary for the middle- or large-sizeddevices.

Preferably, the middle- or large-sized battery module is manufacturedwith small size and small weight if possible. For this reason, aprismatic battery or a pouch-shaped battery, which can be stacked withhigh integration and has a small weight to capacity ratio, is usuallyused as a battery cell of the middle- or large-sized battery module.Especially, much interest is currently generated in the pouch-shapedbattery, which uses an aluminum laminate sheet as a sheathing member,because the weight of the pouch-shaped battery is small, themanufacturing costs of the pouch-shaped battery are low, and it is easyto modify the shape of the pouch-shaped battery.

For the middle- or large-sized battery module to provide output andcapacity required by a predetermined apparatus or device, it isnecessary for the middle- or large-sized battery module to beconstructed in a structure in which a plurality of battery cells areelectrically connected in series with each other, and the battery cellsare stable against an external force.

Consequently, when a middle- or large-sized battery module isconstructed using a plurality of battery cells, a plurality of membersfor mechanical coupling and electrical connection between the batterycells are generally needed, and, as a result, a process for assemblingthe mechanical coupling and electrical connection members is verycomplicated. Furthermore, there is needed a space for coupling, welding,or soldering the mechanical coupling and electrical connection members,with the result that the total size of the system is increased. Theincrease in size of the system is not preferred in the aspect of thespatial limit of an apparatus or device in which the middle- orlarge-sized battery module is mounted. Furthermore, the middle- orlarge-sized battery module must be constructed in a more compactstructure in order that the middle- or large-sized battery module iseffectively mounted in a limited inner space, such as a vehicle.

In addition, a power switching module used to manufacture the middle- orlarge-sized battery module includes a plurality of control elements forwithdrawing electricity of the battery module to the outside. As aresult, the structure of the power switching module is very complicated,and it is difficult to assembly the power switching module.

Consequently, there is a high necessity for a power switching module,used in a battery module assembly, which has an optimum arrangementstructure suitable to a specific structure of the battery moduleassembly such that the power switching module can be electrically ormechanically coupled to the battery module assembly while the powerswitching module is structurally stable.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made to solve the aboveproblems, and other technical problems that have yet to be resolved.

Specifically, it is an object of the present invention to provide apower switching module for battery module assemblies, which has anoptimum compact arrangement structure in which the power switchingmodule is stably mounted in a limited space of a vehicle while the powerswitching module has a minimum space occupation, which is easilyassembled, and which has a high structural stability against externalimpacts.

In accordance with one aspect of the present invention, the above andother objects can be accomplished by the provision of a power switchingmodule for a battery module assembly constructed in a structure in whicha plurality of rectangular battery modules, each having a plurality ofbattery cells or unit modules connected in series to each other, arestacked in the width direction (the longitudinal direction) and theheight direction (the transverse direction) by at least twos such thatthe rectangular battery modules generally constitute a hexahedralstructure (hexahedral stack), outer edges of the hexahedral stack arefixed by a frame member, and input and output terminals of therectangular battery modules are oriented such that the input and outputterminals of the rectangular battery modules are directed toward onesurface (a) of the hexahedral stack, wherein the power switching modulecomprises an insulative substrate mounted to the surface (a) of thehexahedral stack in a coupling fashion, elements mounted on theinsulative substrate for controlling voltage and current during thecharge and discharge of the rectangular battery modules ('controlelements'), and connection members mounted on the insulative substratefor interconnecting the control elements.

For example, the control elements, which prevent overcurrent andovervoltage, during the charge and discharge of the battery modules, andcontrols electricity such that the battery modules are stably operated,and the connection members, which interconnect the control elements, maybe referred to as a power switching module (PSM), which is an elementrequired to construct a middle- or large-sized battery module assembly.

According to the present invention, the PCM is mounted at the surface ofthe battery module assembly where the input and output terminals of thebattery modules are located while the PSM is placed on the substrate.Consequently, the electrical connection structure is further simplified,and therefore, the assembly process is further simplified. Also, thelength of the electrical connection unit is reduced, and therefore, theincrease of the internal resistance is prevented. In addition, apossibility of a short circuit at the connection unit due to externalimpacts is reduced. Furthermore, the input and output terminals, whichhave a strong possibility of a short circuit occurring and arestructurally weak, are protected from external environment.

Preferably, the PSM is constructed in a structure in which the PSM has asize approximately similar to one side of the battery module assemblysuch that the PSM can be appropriately mounted to a predetermine regionof the battery module assembly, and the PSM is mounted to the respectiveinput and output terminals of the rectangular battery modulesconstituting the battery module assembly in a coupling fashion such thatthe electrical connection between the PSM and the input and outputterminals of the rectangular battery modules is accomplished.

The kinds of the control elements constituting the PSM may be various.In a preferred embodiment, the control elements include a main relay forautomatically interrupting overcurrent and overvoltage in a reversiblefashion, a free charge relay connected to the main relay according topriority, during the initial discharge process, for dropping voltage andcurrent to prevent electricity having a high voltage from being abruptlysupplied to a motor and an electric device of a vehicle, a resistanceconnected to the free charge relay for reducing current and voltage, aservice plug located on the route of a cathode or anode circuit formanually interrupting electricity when it is necessary to conform theoperation of the battery modules and repair the battery modules, and acurrent sensor for detecting current on a cathode or anode connectioncircuit and transmitting the detected current to a battery managementsystem (BMS). These control elements appropriately control the voltageand current of electricity generated according to the charge anddischarge of the battery modules.

The hexahedral stack of the battery modules may be constructed invarious structures depending upon the stack shape of the rectangularbattery modules, constituting the hexahedral stack. Preferably, thehexahedral stack of the rectangular battery modules is constructed in astructure in which two rectangular battery modules are arranged in thetransverse direction, such that the rectangular battery modules areopposite to each other, and one or more rectangular battery modules arearranged in the longitudinal direction with respect to the respectiverectangular battery modules.

In the above description, “the opposite arrangement” means that thecorresponding regions of the two rectangular battery modules face eachother. For example, when each rectangular battery module is constructedin a structure in which the input and output terminals are located atone side of each rectangular battery module, the rectangular batterymodules are arranged opposite to each other such that the input andoutput terminals of the rectangular battery modules may be directedtoward the side (a) of the hexahedral stack. This opposite arrangementstructure has an advantage to further simplify the construction forelectrical connection.

Preferably, the battery cells or the unit modules in the respectiverectangular battery modules are arranged in parallel to a pair ofopposite surfaces (b, c) of the hexahedral stack, in order to accomplisha high spatial utilization. In this case, therefore, the rectangularbattery modules are arranged in parallel to the opposite surfaces (b, c)of the hexahedral stack. A coolant flows through gaps defined betweenthe respective rectangular battery modules to effectively remove heatgenerated from the battery cells during the charge and discharge of thebattery cells.

On the other hand, the frame member, which fixes the rectangular batterymodules, fixes only the outer edges of the hexahedral stack. Preferably,therefore, hermetically sealing members are mounted to the oppositesurfaces (b, c) to guide the coolant such that the coolant limitedlyflows in a predetermined direction and, at the same time, to reduce thetemperature deviation between the outer and inner rectangular batterymodules.

Specifically, the hermetically sealing members, which are mounted to theopposite surfaces (b, c) of the hexahedral stack, respectively, closethe opposite side surfaces of the hexahedral stack, whereby the coolantflows only through the hexahedral stack. Consequently, when thehermetically sealing members are not mounted, relatively rapid coolingof the outer rectangular battery modules, which are exposed outward, isprevented. Generally, rapid cooling of the battery modules is preferred.However, the high cooling rate of some battery modules in a middle- orlarge-sized battery system causes unbalance between the battery modules,and the unbalance between the battery modules eventually accelerates thedegradation of the battery cells. Consequently, the hermetically sealingmembers form a channel for the coolant (air) and, at the same time,serve to increase the uniformity between the battery modules.

Preferably, the hermetically sealing members are constructed in astructure in which the hermetically sealing members are bent to form acoolant flow channel at the inside opposite to the battery modules.Also, the hermetically sealing members are preferably made of aninsulating material to further increase the uniformity between thebattery modules, as described above. Especially, the hermeticallysealing members are made of a foamed resin to increase an insulationproperty of the battery module assembly while minimizing the totalweight of the battery module assembly.

The battery modules are connected to an external circuit via the PSM.Consequently, the final input and output terminals of the batterymodules are connected to the PSM, and the electrical connection betweenthe battery modules and the external circuit is accomplished through thePSM.

In a preferred embodiment, when the input and output terminals of thebattery modules protrude to a predetermined region of the insulativesubstrate at the surface (a) of the hexahedral stack, constituted by thebattery modules, the service plug is located at the opposite side of theinput and output terminals of the battery modules, the main relay islocated at the central region of the insulative substrate, an externalinput and output terminal, through which electricity is supplied to anelectric device, such as a low voltage DC-DC converter (LDC), is locatedat one side of the service plug, the resistance is located at the sidediagonally opposite to the service plug, the free charge relay islocated at the side of the service plug and above the resistance, andthe current sensor is located between the main relay and the externalinput and output terminal. With this structure, it is possible tooptimally arrange the control elements in a limited space and tominimize an electrical wiring route for connection between the controlelements.

The connection members are members for electrically interconnecting thecontrol elements. For example, the connection members may be bus bars orwires. Preferably, bus bars, which are made of a metal plate, are usedas the connection members such that the plurality of control elements(the main relay, the free charge relay, the service plug, the externalinput and output terminal, the resistance, and the current sensor),mounted on the substrate, constitute a compact connection structure.

When electricity having an overcurrent and overvoltage is applied to thebattery modules or electricity having an overcurrent and overvoltage isgenerated from the battery modules, the power switching module accordingto the present invention serves to interrupt such an overcurrent andovervoltage. Also, when the inspection or replacement of the batterymodules is necessary, the power switching module according to thepresent invention serves to cause the occurrence of a short circuit.Consequently, it is positively necessary for the cathodes and/or theanodes of the battery modules to be connected to the external circuitvia the power switching module.

Specifically, one of the input and output terminals of each rectangularbattery module, i.e., the cathode or the anode of each rectangularbattery module, may construct a connection circuit having a sequence ofthe service plug, the main relay, the free charge relay, the currentsensor, and the external input and output terminal, and the other inputand output terminal of each rectangular battery module, i.e., the anodeor the cathode of each battery module, may construct a connectioncircuit only having a sequence of the service plug and the externalinput and output terminal. The electrode passing through the pluralityof control elements may be the cathode or the anode.

Preferably, when the substrate is mounted on the surface (a) of thehexahedral stack, constituted by the battery modules, the external inputand output terminal and the service plug of the PSM are located togethersuch that the service plug and the external input and output terminalare exposed to the side of the substrate. Consequently, even when thePSM is assembled in a state in which all the other sides of thesubstrate are hermetically sealed or the access to the substrate isstructurally difficult, the access to the service plug and the externalinput and output terminal is possible through the open one side of thesubstrate. Consequently, the flexibility in designing the apparatus isincreased, and the electrical connection work or the short circuitingwork is easily performed, if necessary.

The frame member, which fixes the outer edges of the hexahedral stack,constituted by the rectangular battery modules, may be constructed invarious structures. For example, the frame member may be constructed ina structure in which all frames for fixing twelve edges of thehexahedral stack are integrally formed or in which frames for fixing atleast four edges of the hexahedral stack constituting one surface of thehexahedral stack are integrally formed.

Preferably, the frame member is constructed in a structure in whichframes for fixing every four edges of the hexahedral stack located atopposite surfaces in the transverse direction are integrally formed, andthe remaining individual frames are coupled to the integrated frames. Inthis coupling structure, for example, the individual frames are used bytwos such that the upper-row battery modules are fixed as a set, thelower-row battery modules are also fixed as another set, and the twointegrated frames are coupled to the individual frames, whereby theassembly process of the battery module assembly is easily performed, andtherefore, the assembly efficiency is improved.

As described above, the insulative substrate, on which the controlelements and the connection members are mounted, may be coupled andmounted to the surface of the surface (a) of the hexahedral stack,constituted by the battery modules, i.e., the surface of the hexahedralstack where the input and output terminals of the rectangular batterymodules are oriented, in various structures. Preferably, coupling partsprotrude from opposite lateral sides of the substrate, and the substrateis stably mounted at the open right side of the frame member, includingthe integrated front frame, the integrated rear frame, the upper rightframe, and the lower right frame, using coupling members, such as bolts.

In this mounting structure, therefore, the insulative substrate not onlyprovides a space for allowing the control elements and the connectionmembers to be received therein, but also serves as a structural body forsupporting the frame member.

The middle- or large-sized battery module assembly includes a batterymanagement system (BMS) for controlling the operation of the batterymodules. According to circumstances, the BMS is further included in thePSM according to the present invention. Specifically, the BMS may bemounted together with the control elements and the connection members onthe insulative substrate coupled to the frame member which fixes theedges of the hexahedral stack at one surface of the hexahedral stack,constituted by the battery modules.

In accordance with another aspect of the present invention, there isprovided a battery module assembly including the power switching module.Specifically, the battery module assembly according to the presentinvention includes rectangular battery modules, constituting ahexahedral stack, where the charge and discharge are performed, and aPSM mounted to one side of the hexahedral stack.

The battery module assembly according to the present invention may beused as a power source for electric vehicles or hybrid electricvehicles, which have a limited installation space and are exposed tofrequent vibration and strong impact, in consideration of theinstallation efficiency and structural stability of the battery moduleassembly. Preferably, the battery module assembly according to thepresent invention is used as a power source for hybrid electricvehicles.

In accordance with a further aspect of the present invention, there isprovided a hybrid electric vehicle including the battery module assemblyas a power source. The hybrid electric vehicle, including the batterymodule assembly that can be charged and discharged, is well known in theart to which the present invention pertains, and therefore, a detaileddescription thereof will not be given.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a perspective view illustrating a battery module assemblyconstructed in a structure in which rectangular battery modules, whichconstitute a hexahedral stack, are fixed by a frame member;

FIG. 2 is a perspective view illustrating a structure in which a powerswitching module (PSM) is mounted to one side of the frame member whilethe hexahedral stack is removed from the battery module assembly of FIG.1;

FIG. 3 is a front perspective view illustrating the PSM and a batterymanagement system (BMS) mounted to one side of the hexahedral stack inthe battery module assembly of FIG. 1;

FIG. 4 is a rear perspective view of FIG. 3;

FIGS. 5 and 6 are a perspective view and a plan view illustrating thestructure of the PSM shown in FIG. 3, respectively;

FIG. 7 is a perspective view illustrating the structure of the BMS shownin FIG. 3; and

FIG. 8 is an exploded perspective view illustrating the coupling betweenthe battery module assembly and a vehicle mounting frame.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Now, preferred embodiments of the present invention will be described indetail with reference to the accompanying drawings. It should be noted,however, that the scope of the present invention is not limited by theillustrated embodiments.

FIG. 1 is a perspective view typically illustrating a battery moduleassembly according to a preferred embodiment of the present inventionconstructed in a structure in which rectangular battery modules, whichconstitute a hexahedral stack, are fixed by a frame member. Forconvenience of easy understanding, FIG. 2 is a perspective viewtypically illustrating a structure in which a power switching module(PSM) is mounted to one side of the frame member while the hexahedralstack is removed from the battery module assembly of FIG. 1. Also, FIG.3 is a front perspective view typically illustrating the PSM and mountedto one side of the hexahedral stack in the battery module assembly ofFIG. 1, and FIG. 4 is a rear perspective view of FIG. 3.

Referring to these drawings, the battery module assembly 100 includessix rectangular battery modules 201, 202, 203, 204, 205, and 206, aframe member 300 for fixing outer edges of a hexahedral stack 200 a,which is constituted by the six rectangular battery modules 201, 202,203, 204, 205, and 206, and a PSM 400. The battery module assembly 100is generally constructed in the shape of a rectangular parallelepiped.

The six rectangular battery modules 201, 202, 203, 204, 205, and 206 arearranged in a structure in which the six rectangular battery modules201, 202, 203, 204, 205, and 206 are stacked by twos in the transversedirection, and the six rectangular battery modules 201, 202, 203, 204,205, and 206 are stacked by threes in the longitudinal direction. Also,the six rectangular battery modules 201, 202, 203, 204, 205, and 206 arestacked in a facing arrangement structure in which input and outputterminals 240 formed at one side of the six rectangular battery modules201, 202, 203, 204, 205, and 206 are adjacent to each other.Specifically, the upper-row battery modules 201, 202, and 203 arestacked on the lower-row battery modules 204, 205, and 206 while theupper-row battery modules 201, 202, and 203 are upside down such thatthe upper-row battery modules 201, 202, and 203 are symmetrical to thelower-row battery modules 204, 205, and 206 about an imaginary centralline.

Each of the rectangular battery modules 201, 202, 203, 204, 205, and 206is constructed in a structure in which a plurality of plate-shaped unitmodules are mounted in each of the rectangular battery modules 201, 202,203, 204, 205, and 206 while the plate-shaped unit modules are erected.The frame member 300 is constructed in a structure in which a pluralityof frames are coupled to each other such that twelve outer edges of thehexahedral stack 200 a are stably fixed by the frames. While thehexahedral stack 200 a is mounted in the frame member 300, six faces ofthe hexahedral stack 200 a are exposed to the outside.

The PSM 400 is mounted on the front of the hexahedral stack 200 a, wherethe input and output terminals 240 are located, for conducting currentto perform charge and discharge, if necessary, performing appropriatevoltage drop during the commencement of the operation of the batterysystem or the disassembly of the battery system, performing electricalconnection with the rectangular battery modules, and protecting acircuit from overcurrent or overvoltage. Since the input and outputterminals 240 of the rectangular battery modules 201, 202, 203, 204,205, and 206 are adjacent to each other, the connection of the PSM 400is easily accomplished, and it is possible to greatly reduce the lengthof a member for electrical connection. Also, the PSM 400 is mounted insuch a manner that the PSM 400 hermetically seals the input and outputterminals 240. Consequently, it is possible to prevent the occurrence ofa short circuit, which may be caused due to the exposure of the inputand output terminals 240. Also, it is possible to prevent the input andoutput terminals 240, which are structurally weak, from being deformedby an external force. Specifically, the PSM 400 also serves as a kind ofprotecting member for protecting the input and output terminals 240 ofthe rectangular battery modules 201, 202, 203, 204, 205, and 206. Thedetails of the PSM 400 will be described hereinafter in detail withreference to FIGS. 5 and 6.

FIGS. 5 and 6 typically illustrate the structure of a PSM according to apreferred embodiment of the present invention.

Referring to these drawings, the PSM 400 is constructed in a structurein which various control elements are mounted on an insulative thickplastic substrate 410, and the control elements are connected to eachother via a bus bar 424 and a wire 430.

When the introduction position of the wire connected to the input andoutput terminals of the battery modules is the lower side of thesubstrate 410, a service plug 414 is located at the upper side of thesubstrate 410, a main relay 416 is located at the central region of thesubstrate 410, a free charge relay 420 is located at the opposite sideof the substrate 410 corresponding to the wire, a resistance 418 islocated below the free charge relay 420, and a current sensor 422 islocated above the free charge relay 420. Consequently, the PSM 400 isconstructed in a compact structure that can be mounted in a limitedspace.

An external input and output terminal is located at one side of theservice plug 414. A cathode external input and output terminal 426 andan anode external input and output terminal 428 are connected to adifferent electric device (not shown), such as an inverter and a lowvoltage DC-DC converter (LDC), via a connection member, such as a cableor wire.

The cathode input and output terminals 240 of the battery modules, whichconstitute the hexahedral stack 200 a of FIG. 1, are connected to acathode connection terminal 432, which is connected to the service plug414, and are connected to the cathode external input and output terminal426 through the main relay 416, the free charge relay 420, and thecurrent sensor 422. On the other hand, the anode input and outputterminals 242 of the battery modules, are connected to an anodeconnection terminal 434, which is connected to the service plug 414, andare directly connected to the anode external input and output terminal428, not through the control elements. Consequently, when one of thecontrol elements, constituting the PSM, i.e., the service plug 414, themain relay 416, and the free charge relay 420 are turned off, a shortcircuit occurs.

The service plug 414 serves to cause the occurrence of a short circuit,if necessary, so as to secure the safety of an operator and the systemduring the assembly and inspection of the battery module assembly orduring the replacement of the battery modules or some of the controlelements.

When the electricity applied to the battery modules or the electricitygenerated from the battery modules has a current or voltage exceeding aprescribed value, the main relay 416 serves to interrupt such a highcurrent or voltage to secure the safety of the system.

The free charge relay 420 and the resistance 418, which is cooperatedwith the free charge relay 420, serve to allow electricity having anappropriated dropped voltage and current to be conducted such that thesystem is prevented from being overloaded due to instantaneous currentconduction, when the current is conducted while the system is stopped,for example, when the vehicle is started. Consequently, when the vehicleis started, the free charge relay 420 is operated, and, when reaching anappropriate operating condition, the free charge relay 420 is notoperated any longer.

On the other hand, the insulative plastic substrate 410 is constructedin a structure in which the insulative plastic substrate 410 has a shapeand size to be exactly mounted at the open right side of the framemember including an integrated front frame, an integrated rear frame, anupper right frame, and an upper lower frame as shown in FIG. 2, andcoupling parts 412 protrude from opposite lateral sides of theinsulative plastic substrate 410. As a result, at least two edges of theinsulative plastic substrate 410 are stably coupled to the frame memberon one side of the battery module assembly.

Consequently, the plastic substrate 410 of the PSM 400 not only providesa space for allowing the related elements, the bus bar, and the wire tobe received therein, but also serves as a structural body for supportingthe frame member.

FIG. 7 is a perspective view typically illustrating the structure of abattery management system (BMS).

Referring to FIG. 7, the BMS 500 is mounted at a position where the PSMis mounted in a housing case of the battery module assembly such thatthe BMS 500 is adjacent to the LDC and the inverter. At the lower partof one side of the BMS 500 is formed a coupling part 504, whichprotrudes outward from the BMS 500. The BMS 500 is fixed to apredetermined region of the battery module assembly by threadedlyengaging a coupling member, such as a bolt, into a coupling hole 502 ofthe coupling part 504. The position where the BMS 500 is mounted may bevariously changed. Preferably, the BMS 500 is mounted at the positionwhere the PSM is mounted as shown in FIG. 8.

FIG. 8 is an exploded perspective view illustrating the coupling betweenthe battery module assembly and a mounting frame member.

Referring to FIG. 8, the mounting frame member 380 is constructed in astructure in which the mounting frame member 380 is gently bent suchthat the mounting frame member 380 protrudes outward while opposite endsof the mounting frame member 380 are coupled to a bent extension part353 of an integrated front frame 350. Also, the mounting frame member380 is provided with coupling grooves for coupling an external apparatusor device (not shown) in addition to coupling grooves for coupling withthe front frame 350.

Consequently, the battery module assembly 100 is effectively mounted tothe external apparatus or device by the mounting frame member 380, whilethe PSM 400 and BMS 500 are mounted at one side of the battery moduleassembly 100.

Although the preferred embodiments of the present invention have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

INDUSTRIAL APPLICABILITY

As apparent from the above description, the power switching module forbattery module assemblies according to the present invention has acompact and optimum arrangement structure in which the power switchingmodule is stably mounted in a limited space, such as an electric vehicleor a hybrid electric vehicle, while the power switching module has aminimum space occupation. Furthermore, the power switching module iseasily assembled and has a high structural stability against externalimpacts.

What is claimed is:
 1. A power switching module for a battery moduleassembly constructed in a structure in which a plurality of rectangularbattery modules, each having a plurality of battery cells or unitmodules connected in series to each other, are stacked in a longitudinaldirection and a transverse direction by at least twos such that therectangular battery modules generally constitute a hexahedral stack,outer edges of the hexahedral stack are fixed by a frame member, andinput and output terminals of the rectangular battery modules areoriented such that the input and output terminals of the rectangularbattery modules are directed toward one surface (a) of the hexahedralstack, wherein the power switching module comprises an insulativesubstrate mounted to the surface (a) of the hexahedral stack in acoupling fashion, control elements mounted on the insulative substratefor controlling voltage and current during the charge and discharge ofthe rectangular battery modules, and connection members mounted on theinsulative substrate for interconnecting the control elements.
 2. Thepower switching module according to claim 1, wherein the controlelements include a main relay for automatically interrupting overcurrentand overvoltage in a reversible fashion, a free charge relay connectedto the main relay according to priority, during the initial dischargeprocess, for dropping voltage and current, a resistance connected to thefree charge relay for reducing current and voltage, a service plug formanually interrupting electricity, and a current sensor for detectingcurrent on a cathode or anode connection circuit.
 3. The power switchingmodule according to claim 2, wherein, when the input and outputterminals of the battery modules protrude to a predetermined region ofthe insulative substrate at the surface (a) of the hexahedral stack,constituted by the battery modules, the service plug is located at theopposite side of the input and output terminals of the battery modules,the main relay is located at the central region of the substrate, anexternal input and output terminal is located at one side of the serviceplug, the resistance is located at the side diagonally opposite to theservice plug, the free charge relay is located at the side of theservice plug and above the resistance, and the current sensor is locatedbetween the main relay and the external input and output terminal. 4.The power switching module according to claim 3, wherein, when thesubstrate is mounted on the surface (a) of the hexahedral stack,constituted by the battery modules, the service plug and the externalinput and output terminal are located together such that the serviceplug and the external input and output terminal are exposed to the sideof the substrate.
 5. The power switching module according to claim 2,wherein the cathodes or the anodes of the battery modules construct aconnection circuit having a sequence of the service plug, the mainrelay, the free charge relay, the current sensor, and the external inputand output terminal, and the anodes or the cathodes of the batterymodules construct a connection circuit having a sequence of the serviceplug and the external input and output terminal.
 6. The power switchingmodule according to claim 1, wherein the hexahedral stack of therectangular battery modules is constructed in a structure in which tworectangular battery modules are arranged in the transverse direction,such that the rectangular battery modules are opposite to each other,and one or more rectangular battery modules are arranged in thelongitudinal direction with respect to the respective rectangularbattery modules.
 7. The power switching module according to claim 6,wherein the battery cells or the unit modules in the respectiverectangular battery modules are arranged in parallel to a pair ofopposite surfaces (b, c) of the hexahedral stack, and hermeticallysealing members are mounted to the opposite surfaces (b, c).
 8. Thepower switching module according to claim 1, wherein the connectionmembers are bus bars formed in the shape of a plate.
 9. The powerswitching module according to claim 1, wherein the frame member isconstructed in a structure in which all frames for fixing twelve edgesof the hexahedral stack are integrally formed or in which frames forfixing at least four edges of the hexahedral stack constituting onesurface of the hexahedral stack are integrally formed.
 10. The powerswitching module according to claim 1, wherein the frame member isconstructed in a structure in which frames (A) for fixing every fouredges of the hexahedral stack located at a pair of surfaces (b, c)opposite to each other are integrally formed, and the remainingindividual four frames are coupled to the frames (A).
 11. The powerswitching module according to claim 10, wherein coupling parts protrudefrom opposite lateral sides of the insulative substrate, and theinsulative substrate is mounted at the open right side of the framemember, including the integrated front frame, the integrated rear frame,the upper right frame, and the lower right frame.
 12. The powerswitching module according to claim 1, further comprising: a batterymanagement system (BMS).
 13. A battery module assembly including thepower switching module according to claim
 1. 14. The battery moduleassembly according to claim 13, wherein the battery module assembly isused as a power source for hybrid electric vehicle.
 15. A hybridelectric vehicle including the battery module assembly according toclaim 13 as a power source.
 16. The power switching module according toclaim 1, wherein the control elements include a main relay forautomatically interrupting overcurrent and overvoltage in a reversiblefashion, a free charge relay connected to the main relay according topriority, during the initial discharge process, for dropping voltage andcurrent, a resistance connected to the free charge relay for reducingcurrent and voltage, and a current sensor for detecting current on acathode or anode connection circuit.